Better spacing on printout

board.cc

@@ -18,7 +18,9 @@
 
 #include "board.h"
 
+#include <cmath>
 #include <cstdlib>
+#include <iomanip>
 #include <iostream>
 
 Board::Board(const int size) : Board(size, BoardInitializer::EMPTY) {}
@@ -60,9 +62,12 @@ int Board::at(const int row, const int column) const {
 }
 
 void Board::print() const {
+  // Define how many digits are required, at max, to print each value in this board.
+  const int value_width = std::floor(std::log10(size_)) + 1;
+
   for (int row = 0; row < size_; ++row) {
     for (int column = 0; column < size_; ++column) {
-      std::cout << board_[row][column] << " ";
+      std::cout << std::setw(value_width) << board_[row][column] << " ";
     }
     std::cout << std::endl;
   }

puzzle.cc

@@ -18,10 +18,13 @@
 
 #include "puzzle.h"
 
-#include "board.h"
+#include <cmath>
 #include <cstdlib>
+#include <iomanip>
 #include <iostream>
 
+#include "board.h"
+
 template <typename T>
 int compute_visibility(T begin, T end) {
   int visible_cells = 0;
@@ -68,20 +71,24 @@ Puzzle::Puzzle(const Board& board) : Puzzle(board.size()) {
 }
 
 void Puzzle::print() const {
-  std::cout << "  ";
+  // Define how many digits are required, at max, to print each value in this puzzle.
+  const int value_width = std::floor(std::log10(size_)) + 1;
+
+  std::cout << std::setw(value_width) << " ";
   for (const int v: top_) {
-    std::cout << v << " ";
+    std::cout << std::setw(value_width) << v << " ";
   }
   std::cout << std::endl;
 
   for (int row = 0; row < size_; ++row) {
-    std::cout << left_[row] << "           "
-              << right_[row] << std::endl;
+    std::cout << std::setw(value_width) << left_[row]
+              << std::setw((value_width + 1) * size_ - 1) << ""
+              << std::setw(value_width) << right_[row] << std::endl;
   }
 
-  std::cout << "  ";
+  std::cout << std::setw(value_width) << " ";
   for (const int v: bottom_) {
-    std::cout << v << " ";
+    std::cout << std::setw(value_width) << v << " ";
   }
   std::cout << std::endl;
 }